Systematic (IUPAC) name
(S)-2-amino-3-(4-chlorophenyl)propanoic acid
Clinical data
Pregnancy cat.  ?
Legal status  ?
CAS number 7424-00-2
ATC code None
PubChem CID 4652
ChemSpider 4491 YesY
KEGG D04143 YesY
Chemical data
Formula C9H10ClNO 
Mol. mass 199.634 g/mol
SMILES eMolecules & PubChem
 YesY(what is this?)  (verify)

Fenclonine, also known as para-chlorophenylalanine (PCPA), is a synthetic amino acid which acts as a selective and irreversible inhibitor of tryptophan hydroxylase, which is a rate-limiting enzyme in the biosynthesis of serotonin.[1] Fenclonine consequently depletes serotonin in the body and reduces its actions, acting as an indirect serotonin antagonist. It is used in scientific research to investigate the effects of serotonin depletion on behaviour.[2]

See also


  1. ^ Jéquier E, Lovenberg W, Sjoerdsma A. Tryptophan hydroxylase inhibition: the mechanism by which p-chlorophenylalanine depletes rat brain serotonin. Molecular Pharmacology. 1967 May;3(3):274-8. PMID 6037686
  2. ^ O'Leary OF, Bechtholt AJ, Crowley JJ, Hill TE, Page ME, Lucki I. Depletion of serotonin and catecholamines block the acute behavioral response to different classes of antidepressant drugs in the mouse tail suspension test. Psychopharmacology (Berlin). 2007 Jun;192(3):357-71. PMID 17318507